Progesteron only injection

Question 1

Progesteron only injection: How it works

Answer 1

Primarily by preventing ovulation

Question 2

Progesteron only injection: Duration of use

Answer 2

Repeat injections needed every 12 weeks (DPMA) or 8 weeks (NET‑EN)

Question 3

Progesteron only injection: Failure rate

Answer 3

• Fewer than 0.4 in 100 over 2 years

- Pregnancy rates lower for DPMA than NET‑EN

Question 4

Progesteron only injection: Effect on periods

Answer 4

• Amenorrhoea common, and is more likely with DMPA than NET‑EN, and with longer use; not harmful
• Persistent bleeding may occur

Question 5

Progesteron only injection: Other risks

Answer 5

• Up to 50% of women stop using DMPA by 1 year; the most common reason is an altered bleeding pattern, such as persistent bleeding
• Weight gain: may be up to 2–3 kg over a year on DMPA
• Bone mineral density: DMPA use is associated with small loss; largely recovered when DMPA is stopped
• No evidence that fracture risk is increased
  -No evidence of effect of DMPA on:
  Depression
  Acne
  Headaches

Question 6

Progesteron only injection: Return of fertility

Answer 6

• Can take up to a year

- Women who do not want to get pregnant should start a different contraceptive as soon as they stop injections

Question 7

Progesteron only injection: At the time of fitting

Answer 7

Return for next injection, or if problems

Question 8

Progesteron only injection: population

Answer 8

• Avoid in adolescents, but it may be given if other methods are not suitable or acceptable
• Avoid in women older than 40 years, but in general the benefits outweigh the risks, and it may be given if other methods are not suitable or acceptable
• Women with a body mass index over 30 can safely use DMPA and NET‑EN
• Women who are breastfeeding can consider using injectable contraceptives

Question 9

Progesteron only injection: timing of fitting

Answer 9

• Up to and including the fifth day of the menstrual cycle without the need for additional contraceptive protection
• At any other time in the menstrual cycle, but additional barrier contraception should be used for the first 7 days after the injection
• Immediately after first‑ or second‑trimester abortion, or at any time thereafter
• At any time post‑partum.

Question 10

Progesteron only injection: f/up

Answer 10

• Women attending up to 2 weeks late for repeat injection of DMPA may be given the injection without the need for additional contraceptives
• A pattern of persistent bleeding associated with DMPA use can be treated with mefenamic acid or ethinylestradiol
• Women who wish to continue DMPA use beyond 2 years should have their individual clinical situations reviewed, the balance between the benefits and potential risks discussed, and be supported in their choice of whether or not to continue
• Healthcare professionals should be aware that if pregnancy occurs during DMPA use there is no evidence of congenital malformation to the fetus